Abstract: The present invention relates to a novel endoproteolytic hatching enzyme called zonase. The new enzyme is a non-selfdegrading endoprotease. The inventors have purified the enzyme to sequence grade, this was made possible due to the described purification method, which set forth the sequence in which the purification method is to be performed. All preparations of salmon zonases exhibit valuable enzymatic properties with regard to proteolysis, both in terms of catalysis and stability.

Abstract: The present invention relates to a novel endoproteolytic hatching enzyme called zonase. The new enzyme is a non-selfdegrading endoprotease.

Abstract: A procedure is described for obtaining valuable endoproteases (or zonases) from hatchery-produced Atlantic salmon eggs. Synchronized hatching by for instance elevated temperature, is followed by filtration through cheese cloth. The filtrate (hatching fluid) may be stored for months or year (depending on conditions) without loss of activity. Extraneous matters are removed by centrifugation (16,000 g, 2×15 min) after addition of urea (2 or 4 M, or more). High purity zonases are obtained by simple chromatographic procedures (gel filtration, affinity chromatography, isoelectric focusing), yielding sequence-grade purity after all three steps are performed in sequence. All preparations of salmon zonases exhibit valuable enzymatic properties with regard to proteolysis, both in terms of catalysis and stability.